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| author | Valentin Schneider <vschneid@redhat.com> | 2025-10-10 17:38:13 +0200 |
|---|---|---|
| committer | Frederic Weisbecker <frederic@kernel.org> | 2025-10-28 17:32:56 +0100 |
| commit | d1e6d2773898c7a1c19e12619d303920d32a9cd0 (patch) | |
| tree | ade5216f2431cb9d5c6e028b2e01f9e916b9e3d1 /kernel | |
| parent | Linux 6.18-rc1 (diff) | |
| download | linux-d1e6d2773898c7a1c19e12619d303920d32a9cd0.tar.gz linux-d1e6d2773898c7a1c19e12619d303920d32a9cd0.zip | |
rcu: Add a small-width RCU watching counter debug option
A later commit will reduce the size of the RCU watching counter to free up
some bits for another purpose. Paul suggested adding a config option to
test the extreme case where the counter is reduced to its minimum usable
width for rcutorture to poke at, so do that.
Make it only configurable under RCU_EXPERT. While at it, add a comment to
explain the layout of context_tracking->state.
Link: http://lore.kernel.org/r/4c2cb573-168f-4806-b1d9-164e8276e66a@paulmck-laptop
Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcu/Kconfig.debug | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/kernel/rcu/Kconfig.debug b/kernel/rcu/Kconfig.debug index 12e4c64ebae1..625d75392647 100644 --- a/kernel/rcu/Kconfig.debug +++ b/kernel/rcu/Kconfig.debug @@ -213,4 +213,19 @@ config RCU_STRICT_GRACE_PERIOD when looking for certain types of RCU usage bugs, for example, too-short RCU read-side critical sections. + +config RCU_DYNTICKS_TORTURE + bool "Minimize RCU dynticks counter size" + depends on RCU_EXPERT && !COMPILE_TEST + default n + help + This option sets the width of the dynticks counter to its + minimum usable value. This minimum width greatly increases + the probability of flushing out bugs involving counter wrap, + but it also increases the probability of extending grace period + durations. This Kconfig option should therefore be avoided in + production due to the consequent increased probability of OOMs. + + This has no value for production and is only for testing. + endmenu # "RCU Debugging" |